[PATCHv2 0/2] fs/pstore: Use memcpy_from/toio() instead of memcpy.

[PATCHv2 0/2] fs/pstore: Use memcpy_from/toio() instead of memcpy.

[Enric Balletbo i Serra]

Dear all,

These patches were needed in order to make ramoops work in my armv8 board. They
originally come from chrome os kernel, so I kept the original authors. I found
that weren't in mainline so I thought that will be really interesting send them.

Best regards,
Enric

Changes since v1:
 - Added Acked-by: Kees Cook <keescook@chromium.org>

Andrew Bresticker (1):
  fs/pstore: Use memcpy_fromio() to save old ramoops buffer

Furquan Shaikh (1):
  fs/pstore: Use memcpy_toio instead of memcpy

 fs/pstore/ram_core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

-- 
2.1.0

[PATCHv2 1/2] fs/pstore: Use memcpy_toio instead of memcpy

[Enric Balletbo i Serra]

From: Furquan Shaikh <furquan@google.com>

persistent_ram_update uses vmap / iomap based on whether the buffer is in
memory region or reserved region. However, both map it as non-cacheable
memory. For armv8 specifically, non-cacheable mapping requests use a
memory type that has to be accessed aligned to the request size. memcpy()
doesn't guarantee that.

Signed-off-by: Furquan Shaikh <furquan@google.com>
Signed-off-by: Enric Balletbo Serra <enric.balletbo@collabora.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Olof Johansson <olofj@chromium.org>
Tested-by: Furquan Shaikh <furquan@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
---
 fs/pstore/ram_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index 76c3f80..351164d 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -299,7 +299,7 @@ static void notrace persistent_ram_update(struct persistent_ram_zone *prz,
 	const void *s, unsigned int start, unsigned int count)
 {
 	struct persistent_ram_buffer *buffer = prz->buffer;
-	memcpy(buffer->data + start, s, count);
+	memcpy_toio(buffer->data + start, s, count);
 	persistent_ram_update_ecc(prz, start, count);
 }
 
-- 
2.1.0

[PATCHv2 2/2] fs/pstore: Use memcpy_fromio() to save old ramoops buffer

[Enric Balletbo i Serra]

From: Andrew Bresticker <abrestic@chromium.org>

The ramoops buffer may be mapped as either I/O memory or uncached
memory.  On ARM64, this results in a device-type (strongly-ordered)
mapping.  Since unnaligned accesses to device-type memory will
generate an alignment fault (regardless of whether or not strict
alignment checking is enabled), it is not safe to use memcpy().
memcpy_fromio() is guaranteed to only use aligned accesses, so use
that instead.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Enric Balletbo Serra <enric.balletbo@collabora.com>
Reviewed-by: Puneet Kumar <puneetster@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
---
 fs/pstore/ram_core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index 351164d..5308277 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -322,8 +322,8 @@ void persistent_ram_save_old(struct persistent_ram_zone *prz)
 	}
 
 	prz->old_log_size = size;
-	memcpy(prz->old_log, &buffer->data[start], size - start);
-	memcpy(prz->old_log + size - start, &buffer->data[0], start);
+	memcpy_fromio(prz->old_log, &buffer->data[start], size - start);
+	memcpy_fromio(prz->old_log + size - start, &buffer->data[0], start);
 }
 
 int notrace persistent_ram_write(struct persistent_ram_zone *prz,
-- 
2.1.0

Re: [PATCHv2 0/2] fs/pstore: Use memcpy_from/toio() instead of memcpy.

[Kees Cook]

On Mon, Feb 15, 2016 at 12:19 AM, Enric Balletbo i Serra
<enric.balletbo@collabora.com> wrote:
> Dear all,
>
> These patches were needed in order to make ramoops work in my armv8 board. They
> originally come from chrome os kernel, so I kept the original authors. I found
> that weren't in mainline so I thought that will be really interesting send them.
>
> Best regards,
> Enric
>
> Changes since v1:
>  - Added Acked-by: Kees Cook <keescook@chromium.org>

Tony, are you able to pull these?

-Kees

>
> Andrew Bresticker (1):
>   fs/pstore: Use memcpy_fromio() to save old ramoops buffer
>
> Furquan Shaikh (1):
>   fs/pstore: Use memcpy_toio instead of memcpy
>
>  fs/pstore/ram_core.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> --
> 2.1.0
>



-- 
Kees Cook
Chrome OS & Brillo Security

RE: [PATCHv2 0/2] fs/pstore: Use memcpy_from/toio() instead of memcpy.

[Luck, Tony]

> Tony, are you able to pull these?

I've been distracted ... I need to dig into the pile of pending pstore patches.

Was there a consensus on the device tree ones? I saw a "you shouldn't do that",
and a "but it's really convenient and doesn't hurt anyone else" exchange.

-Tony

Re: [PATCHv2 0/2] fs/pstore: Use memcpy_from/toio() instead of memcpy.

[Kees Cook]

On Wed, Feb 17, 2016 at 2:57 PM, Luck, Tony <tony.luck@intel.com> wrote:
>> Tony, are you able to pull these?
>
> I've been distracted ... I need to dig into the pile of pending pstore patches.
>
> Was there a consensus on the device tree ones? I saw a "you shouldn't do that",
> and a "but it's really convenient and doesn't hurt anyone else" exchange.

Honestly, I'm a bit unclear where the DT stuff stands... that thread
got long. :)

-Kees

-- 
Kees Cook
Chrome OS & Brillo Security

Re: [PATCHv2 0/2] fs/pstore: Use memcpy_from/toio() instead of memcpy.

[Enric Balletbo i Serra]

Hi all,

On 18/02/16 00:00, Kees Cook wrote:
> On Wed, Feb 17, 2016 at 2:57 PM, Luck, Tony <tony.luck@intel.com> wrote:
>>> Tony, are you able to pull these?
>>
>> I've been distracted ... I need to dig into the pile of pending pstore patches.
>>
>> Was there a consensus on the device tree ones? I saw a "you shouldn't do that",
>> and a "but it's really convenient and doesn't hurt anyone else" exchange.
>
> Honestly, I'm a bit unclear where the DT stuff stands... that thread
> got long. :)
>
> -Kees
>

There are more pstore related patches in these patch series, would be 
good if you have a chance to look at these also, thanks.

https://lkml.org/lkml/2016/2/16/109

-Enric

Re: [PATCHv2 0/2] fs/pstore: Use memcpy_from/toio() instead of memcpy.

[Olof Johansson]

[From the right account and in text format this time]

On Mon, Feb 29, 2016 at 12:04 AM, Enric Balletbo i Serra
<enric.balletbo@collabora.com> wrote:
> Hi all,
>
> On 18/02/16 00:00, Kees Cook wrote:
>>
>> On Wed, Feb 17, 2016 at 2:57 PM, Luck, Tony <tony.luck@intel.com> wrote:
>>>>
>>>> Tony, are you able to pull these?
>>>
>>>
>>> I've been distracted ... I need to dig into the pile of pending pstore
>>> patches.
>>>
>>> Was there a consensus on the device tree ones? I saw a "you shouldn't do
>>> that",
>>> and a "but it's really convenient and doesn't hurt anyone else" exchange.
>>
>>
>> Honestly, I'm a bit unclear where the DT stuff stands... that thread
>> got long. :)
>>
>> -Kees
>>
>
> There are more pstore related patches in these patch series, would be good
> if you have a chance to look at these also, thanks.
>
> https://lkml.org/lkml/2016/2/16/109

Yeah, those are platform/chrome patches that I'll look at and pick up this week.


-Olof

Re: [PATCHv2 0/2] fs/pstore: Use memcpy_from/toio() instead of memcpy.

[Kees Cook]

On Mon, Feb 15, 2016 at 12:19 AM, Enric Balletbo i Serra
<enric.balletbo@collabora.com> wrote:
> Dear all,
>
> These patches were needed in order to make ramoops work in my armv8 board. They
> originally come from chrome os kernel, so I kept the original authors. I found
> that weren't in mainline so I thought that will be really interesting send them.
>
> Best regards,
> Enric
>
> Changes since v1:
>  - Added Acked-by: Kees Cook <keescook@chromium.org>
>
> Andrew Bresticker (1):
>   fs/pstore: Use memcpy_fromio() to save old ramoops buffer
>
> Furquan Shaikh (1):
>   fs/pstore: Use memcpy_toio instead of memcpy
>
>  fs/pstore/ram_core.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

Eek, these got missed when I took over pstore maintaintership. I've
pulled these for -next now. Thanks!

-Kees

-- 
Kees Cook
Nexus Security